From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Graph showing the results of a battery discharge test.
| Identifier | ExFiles\Box 54\1\ Scan269 | |
| Date | 7th June 1928 | |
| 7-6-28 176 SU 75 a.h. 104 lbs. Average amperes = 6.24 Hours = 3.7 Ampere hours = 23.1 .222 1.80w | ||